There are a number of known methods of smelting iron ore to produce molten iron which are based on the use of a metallurgical vessel (hereinafter referred to as a "smelt reduction vessel") containing a molten bath of iron and slag.
In general terms, these known methods comprise injecting iron ore or partially reduced iron ore and a source of a carbonaceous material into a molten bath of iron and slag. In the molten bath the iron ore or partially reduced iron ore is reduced to metallic iron and melted. The carbonaceous material (in solid or gaseous form) is required as a source of reductant and thermal energy and to carburise the molten bath to produce pig iron (typically 1 to 4 wt. % carbon in metal).
In a number of known processes, reaction gases that are discharged from the smelt reduction vessel are used to preheat and to partially reduce iron ore in a pre-reduction vessel, such as a shaft furnace, prior to transferring the partially reduced iron ore into the smelt reduction vessel. These known processes are commonly described as being two-stage linked processes.